1. Field of the Invention
The present invention relates to an error correction amount creating device for a five-axis machine having three linear axes and two rotation axes, in which at least one of a rotation axis-dependent translation correction amount and a rotation axis-dependent rotation correction amount with respect to the two rotation axes is obtained from measurement data of measurement by a measuring machine to create an error correction amount.
2. Description of the Related Art
In a five-axis machine having three linear axes and two rotation axes, an error dependent on the rotation axis (i.e., an error in accordance with the rotation amount of the rotation axis) occurs when the rotation axis is moved according to a movement instruction. Therefore, in the case of performing machining with high precision, it is necessary to correct the error dependent on the rotation axis with an error correction amount dependent on the rotation axis.
In Japanese Patent Application Laid-open No. 2009-151756 and Journal of Technical Disclosure No. 2009-505137, it is disclosed that an error dependent on a rotation axis is corrected by obtaining the translation error amount and rotation error amount dependent on the rotation axis from measurement data obtained by measurement using a measuring machine and creating an error correction table.
Japanese Patent Application Laid-open No. 2009-151756 mentioned above discloses a technique for a five-axis machine in which a two-dimensional coordinate system space is divided at equal intervals or unequal intervals in each axis direction to obtain, from measurement data for each position of division, the translation error amount and rotation error amount dependent on the rotation axis for each lattice point of lattice regions into which the two-dimensional coordinate system space with the two rotation axes is divided at equal intervals or unequal intervals in each direction.
On the assumption that the error of the center of rotation of the rotation axis does not change along with rotation, Journal of Technical Disclosure No. 2009-505137 discloses a technique for a five-axis machine in which a two-dimensional coordinate system space with two rotation axes is divided into lattice regions of equal intervals or unequal intervals in each axis direction to obtain the translation error amount and rotation error amount dependent on the rotation axis for each lattice point from measurement data of position at which all angles of these two rotation axes are zero.
However, with the technique disclosed in Japanese Patent Application Laid-open No. 2009-151756 mentioned above, measurement of the error for each position of division takes time. With the technique disclosed in Journal of Technical Disclosure No. 2009-505137 mentioned above, a case where the error of the center of rotation of the rotation axis changes along with rotation cannot be dealt with.